Scum collector



May-23, 1939. TARK 2,159,409

SCUM COLLECTOR Filed July 15, 1935 7 Sheets-Sheet 2 Maya/W320.

M. B. TARK SCUM COLLECTOR r May 23, 1939.

Filed July 15. 1935 7 Sheets-Sheet 3 172%622507 Jfarrozgs 2.237% @QA M fforrzqya May 23, 1939. M. B. TAR K I 2,159,409

scum COLLECTOR Jizarvzgs' ,1939 M. B. TARK I 2,159 409 scum COLLECTOR Filed July 15, 1935 7 Sheets-Sheet 5 fzzwzzfa r Jhrcup 2.157%

May 23, 19,39.

M. B. TARK SCUM COLLECTOR Filed July 15, 1935 7 Sheets-Sheet 6 y 3, 1939. M. B. TARK 2,159,409

SCUM COLLECTOR Filed July 15, 1935 7 Sheets-Sheet 7 fwye/zfar Jfafvugj ZZZ Patented May 23, 1939 I UNITED STATES 2,159,4o9 scum conmo'roa Marcus B. Tar-k, Philadelphia, Pa, assignor to Link-Belt Company, Chicago, 111., a corporation of Illinois Application July 15, 1935, Serial No. 31,419

6 Claims.

This invention relates to equipment for removing grease, oil and other floating material from suspended near the surface of liquid within the tank.

It has for oneob'ject to provide means whereby the surface of a body liquid may be swept of scum by simple mechanisms which are caused to I sweep the entire surface. Another object is to provide a scum collector or skimmer'and a sludge 5 collector for collecting, respectively, scum and sludge from a plurality of tanks and for moving them to a discharge. Another object is to provide a machine that collects the scum, concentrated at one end of the tank by another collector,

and discharges it into a trough with aminimum amount of moisture. Another object is to provide automatic means for controlling the skimmer so that in one direction of reciprocation it is in contact with the surface of the liquid and collects the scum, while in the opposite direction of recip- -rocation it is automatically raised and held out of contact with the liquid. Other objects will appear from time to time throughout the specification and claims.

The invention is illustrated more or less diagrammatically in the accompanying drawings, wherein: a

"Figure l is a longitudlnahgenerally vertical,

3 sectional'view of a tank with the scum collector installed; v

. Fig. 2 is a plan view on an enlarged'scale, showing a-portion of the tankandone collecting assembly; Fig. 3 is a side elevation'showingone of the collector assemblies at the scum trough taken on an enlarged scale and with parts of the tank shown in section;

, Fig. 4 is a side elevation showing one of the collector assemblies at the end of the tank with parts of the tank in section; V

Fig. 5 is a section on the line 5-5 of Fig. 3; Fig. dis a plan view of a tank assembly;

Fig. 'l is a transverse vertical section with parts omitted, taken at line of Fig. 6; and

Fig, 8 is a longitudinal vertical section taken at line Hot Fig. 6, showing the sludge cross coll'ector;

Fig. 9 is a View similar to Fig. 1 showing a duplicate installation with one drive operating four scum collecting carriafles.

Like parts are designated by like characters throughout the specification and drawings.

In the form shown the collector is applied to a generally rectangular, elongated tank. It is not, however, limited to this application nor in fact to any particular size or shape of tank. As shown the tank comprises end walls I, a floor or bottom wall 2, and side walls 3. A main partition wall 4 may be installed dividing the tank in the form here showninto two sections of substantially equal length. Partial partitions or baiiles 5 may also be installed at suitable points throughout the tank. These details are illustrated diagrammatically and form no essential part of the present invention Fluid material may be introduced into the tank in any desired manner, by any desired means, not here shown. 'Where a central partition like the member a is used, a scum trough 6 is installed upon or in it. As shown the trough is made so that its upper edges 1 are above-the surface of the fluid within the tank and on each side the scum trough is provided with an inclined surface 8 which slopes upwardly from a point below the surface of the liquid to the upper edge of the scum trough above the surface of theliquid. A pipe 9 or other means for withdrawing the scum from the trough may be provided. Whatever the shape of the scum trough and whatever means are provided for removing scum from the trough, the trough will ordinarily have its upper edges above the surface of the fluid so that material will not enter the trough except when positively moved by some collecting or skimming means.

The scum collecting means comprises, in the form shown, two collecting assemblies which are "substantially alike; Each collector assembly thus comprises a truck formed of side members Ill and cross members ll. Axles I! are journaled in the side members and carry preferably flanged rollers 13 which engage and run upon tracks ll mounted adjacent the tank and preferably along the upper edges of the side walls 3. Extending across betweenthe transverse members I I are frame members I5 and extending upwardly from the transverse members II and preferably generaly above the members l5 are frame members l6. Jou

naled in suitable bearings supported by the members I6 is a shaft ll carrying a sheave l8.

Journaled preferably in the side members III in bearings I9 is the collector shaft 20. Fixed on this shaft is a brake drum 2].; Brake bands -22 contact the brake drum, are fastened at one end to a link or links 23 and are yieldingly drawn 7 towards each other at their other ends by a construction just described is to resist rotation of the shaft 20, but if 'sufilcient force is applied the shaft may turn.

Secured to the shaft 20 are two downwardly depending arms 25. At their lower ends they carrya transverse skimmer or collector blade 26, which may carry a flexible wiper or squeegee 21.

To move the collector assembly along the tracks 4 a cable 28 is provided. It isfastened to one ofthe transverse members II by means of a ring bolt 29 or otherwise, and passes to a driving sheave 30, which by means of gearing 3| is driven from a motor 32. The cable 28 passesv over the sheave and back across the collecting assembly engaging the sheave I8. It passes thence about an idler sheave 33, supported in bearings 34 which are mounted upon a take-up 35. The cable 28 passes thence from below the idler 33 to the second of the cross members H to, which it is attached by means of a ring bolt 36 or otherwise.

Where, as in the form shown herewith, there is more than one collector'assembly, the cable isattached at one end to each of them, passes over the idler sheave on the top of eachand a connecting cable 31 is provided between the two assemblies to attach them together. Whether one or more conveyors are used, they are driven by the cable 28 and move back and forth as it moves.

In the particular form of the invention shown there are two collector assemblies, both driven by the same cable and connected to each other by the cable 31. The collector assemblies comprise the same general parts and may not difier from each other .at all. For some .purposes it is convenient, however, to pivot the shaft 20 which carries the members 25 toward different ends of the truck which carries them, Thus infthe left hand collector assembly the' shaft 20 is pivoted adjacent the right hand as shown 'in Figure '1, while in the right hand collector assembly the shaft 20 is pivoted adjacent the left end. The reason for this is that as the assemblies move back and forth the members 25 contact the end walls of the tank or chamber and it is preferable to have the member which contacts the wall face or curve slightly away from it as indicated in detail in Figure 4 and generally in Figure 1. It is convenient also to provide cams 38 on the inner facesof the end walls, one to be contacted by each of the members 25 and thus the members 25 and the shafts-which carry them are assembled at the appropriate ends of the trucks and are faced with respect to the end walls of the tank so that the blades 26 and 21 do not strike the end walls when the conveyors are in the extreme end position as shown in detail in Figure 4.

Each of the members 25 may have an extension 33 which is in effect a continuation of the member 25 and upon the member 39 a movable counterweight .40 may be mounted. For some purposes this is not necessary and for some purposes only one of each pair of members 125 will carry the extension 39 and the counterweight. The use of the counterweight will be explained below.

in one direction and then another along the ,one place the scum and in another place 2,159,409 spring 24. The eflept of the brake and brake tanks; while any reversing means may be arranged and while the invention is not limited to any particular reversing means, the form shown comprises electric limit switches 42 and 43, as shown in Figures 1 and 4, which may be mounted upon suitable brackets 44 to one of the side walls 3. The limit switches are actuated by a contact cam member 45 carried by the truck of one of the collector assemblies, herein illustrated as secured to the collector assemblyadjacent the driving sheave 30,

The brackets 44 may also support overtravel limit switches 46 and 41 respectlvely, which may be actuated by the cam member 45 if either of the limit switches 42 and 43 fail to reverse the motor 32. The overtravel limit switches 46 and 41 serve to break the electrical circuit through the motor 32 and stops movement of the collecting assemblies.

Limit switches might, of course, be mounted anywhere else to contact any other moving part of the apparatus, When they are moved the limit switches cause reversal of the motor and hence reversal of movement of the collecting assemblies. There is shown in Figures 6, 7 and "8 an assembly of sewage treatment tanks into which material is discharged for treatment, in which settling takes place. Means are shown for moving the scum to one end of several tanks and for moving the sludge to the opposite end of the tanks, and cross collectors are shown for collecting the sludge so moved and moving it to discharge hoppers, and a cross collector orskimmer such as that shown in Figures 1 to 5, inclusive, in detail, is shown generally in Figures 6 to 8, inclusive. As so shown ,the scum collector or skimmer is arranged to 'ollect the scum from a plurality of tanks and t discharge itto a, single point of discharge. A's thus shown there, a battery of tanks in which material is treated and through which materi'l is conveyed togoint s of collection where c oss collectors, 0 rating through several tanks and divisions of tanks, collect in sludge for removal from the tanks.

As shown in Figure 6 there are-assembled in one installation a plurality of tanks 48. Fluid material is brought to these tanks for treatment from an influent conduit 43 and is discharged into the various tanks or divisions of the tanks for' the treatment through ports 5!! controlled by valves 5| which may be operated by valve moving mechanisms 52. The various tanks 43 may be divided with partitions 53 which extend partly upward from the bottom of the tanks but do not divide the tanks throughout their total height. Extending laterally across the tanks 48, preferably at their ends adjacent the influent conduit, are a series of sludge collecting troughs 54 each of which terminates at one end in a sludge hopper 55 from which sludge is remove by any suitable means, 56 are eflluent or s t led sewage conduits.

Extending across each of the tanks 48 as indicated in detail in the first five figures, is a scum collecting and discharging mechanism which has been described in detail in connection with the description of the first five figures and need not be described again herewith. Positioned within each of. the sludge collecting troughs is a cross collector for moving sludge toward the sludge hopper 55. This comprises idling sprockets 56a, 56a, and a driven sprocket 51, chains 58 and fiights 59 mounted upon them. These cross collectors are driven in the direction of the arrow 1 2,169,409 in Figure 8 and move sludge to the discharge hopper I.

It will be noticed that a single sludge collector operates throughout the entire length of a tank 48 and collects and discharges into .the hopper the sludge from the whole tank, and that there are preferably three collectors formed of the chains 60 and flights iii in each tank 48, separated from each other by the partitions 53. Similarly the scum collector described above in connection with Figures 1 to 5, inclusive, collects thescum from an entire tank. However, in connection with the scum collector two collectors are mounted with a single drive to discharge scum into a single sump, as illustrated in detail in Figures 1 and 3,

As a means for moving the sludge to the sludge cross collector and for simultaneously moving scum to the scum cross collector, there is positioned in each of the tanks 48 a conveyor comprising chains 60' and flights 61 so arranged that the lower run of the conveyor carries sludge toward the sludge discharge and collecting mechanism while the upper run of the conveyor carries scum toward the scum discharge mechanism. The direction of movement is indicated by the arrows in Figure '7. The chains 60 are positioned about idler sprockets 62, 62, supported in suitable bearings adjacent the bottom of the tank, and idler sprockets 63, adjustablysupported in adjustable bearings adjacent the upper surface of the liquid within the tank. 64 are driving sprockets on a shaft which carries a sprocket 65 and is driven by a chain 66 from a sprocket 61 driven by a motor 68;] or by any other suitable power source.

As shown, the tanks are open or uncovered and only sufiicient'structural parts extend over the surface of the tanks tosupport the driving mechanism and to support the scum cross conveyors.

The driving means for the various conveyors might be changed in many respects and the invention is not limited to the particular means for driving the main conveyors within the tanks nor to the particular means for driving the cross conveyors and the invention contemplates broadly the provision, in connection with a number of tanks, of means for conveying material along the bottom of the tanks and along the surface of the tanks and it further contemplates the association with such conveyors and such multiplicity of tanks of cross conveyors for handling the sludge on the bottom of the-tank and for handling scum and other floating material on the top of the tank, whereby a single cross conveyor handles,

collects and conveys accumulations and discharge from several divisions of a single tank, or in'some cases from a plurality of tanks.

The use and operation of the invention areas follows:

Assume the parts in the position shown in Figure 1. moved against the left hand end wall of the tank. The right hand assembly has been moved against the partition 4, has struck the inclined surface on the right of the scum trough and has moved up along position A to the full line position. In that position it has completed its skimming operation and has discharged the scum into the scum trough and swept the right hand inclined surface 8 clear.

' It continues slightly farther, moving to theleft,

until it reaches the second dotted line position B. It has thus been moved from the first dotted line The left hand assembly has been iV-as indicated in the first dotted line m which the lower portion of the blade 26 ex- .,tends slightly below the water level and it has been tilted to a position in which it is clear of the water. Its tilting movement was resisted by the brake and counterweight assembly.

During the movement of the right hand assembly just described the left hand assembly has moved into contact with the left hand end wall I. The members 25 have contacted the cams or guides 38 and have been swung from the dotted line position C, which they occupied in their movement to the left, and moved into the full line position shown at the left of Figure 1 generally and in detail in Figure 4. Thus the left hand skimmer blade 26 is slightly below the water level while the right hand blade 26 is clear of the water surface. In the dotted line position B of the right hand assembly and full line position of the left hand assembly, the cam member 45 has contacted the limit switch 42 and caused reversal of movement. As the assemblies now move in the reverse or right hand direction the left hand blade 26 collects the scum and moves it toward the scum trough. At the same time the erably to the opposite ends of the tanks.

right hand blade 26 moves to the right but it is above the water and hence clears the water and the scum. It remains in that position until it strikes the right hand end wall of the tank and is swung downward into contact with the water again. As this is occurring the left hand collecting assembly has moved the scum to the left hand side of the scum trough, has carried it up the left hand inclined surface 8 and deposited it in the scum trough. It continues its movement slightly farther until the cam member 45 contacts I the limit switch 43 and the movement of the parts is'again reversed.

Thus as the two collecting assemblies continue to reciprocate, first one skims half of the tank, as it moves ,toward the scum trough, and the other assembly moving in the same direction, rides above the water until it strikes its end wall and is moved into the downward position. Thus each section of the tank is skimmed alternately and the collecting assemblies move back and forth, skimming in one direction, as they move toward the scum trough, and riding clear of the water in the reverse direction as they move away from the scum trough. Note that the cross bar 4| serves to rotate the members 25 to their final position, for example, to the position B, of the right hand assembly in Figure 3, in which they are held by the brake members 2| and 22.

' The operation of the total installation as shown for example in one form in Figures 6, land 8, will now be described. Fluid material for treatment is conveyed into the main influent conduit and is admitted to'the various tanks asdesired. Material remains in the tanks for a period necessary to accomplish the settlement of sludge toward or upon the bottom of the tank. During this period also scum and floating materials of various sorts collect upon or near the surface. During this period while the scum is collecting on the surface and the sludge is collecting at the bottom, the main conveyors which run iongitudinally through the tanks move slowly to carry the sludge toward one end of the tank into the sludge cross troughs and carry the scu ;ref-

When sufficient sludge and scum have accumulated at or near the ends of the tanks the cross conveyors are set in operation and the scum and sludge are moved crosswise of the longitudinally extended position A which is the sldmming position, and tanks and are collected and discharged. Fre- 16 -may be stationary while one or more of them is in motion. While in the assembly shown the tanks are in alignment with each other this need notbe the case and for some installations the tanks will be slightly out of alignment, but what-' ever the relative position of the tanks with respect to each other, means are provided for discharging influent into the tanks, conveying means are provided for moving sludge and scum along the tanks and cross conveying means are provided for collecting the sludge and scum and moving them to suitable discharges.

I claim:

1. In combination, a sewage tank, a trackextending along the wall thereof, a carriage mounted for reciprocation along the track, a scum trough at one end of the tank, located above the level of the sewage, a ramp extending from beneath the sewage level toand terminating at the edge of the trough, "a scum scraper arm pivotally depending from the carriage. a scraper blade carried by the arm, cams in the path of the arm located one of them adjacent the trough, another adjacent the opposed end of the excursion of the arm as it travels with the carriage, means for reciprocating the carriage back and forth across the tank, means associated with the arm and the carriage whereby the arm may be held selectively in such position as to raise the blade above the surface of the liquid and to immerse it in the liquid so as to act as a skimmer, the cam furthest removed from the trough. when contacted by the arm being adapted to rotate it to immerse the blade in the surface as the carriage moves toward thetrough, the blade being adapted to ride up. on the ramp and propel skimmed scum upwardly therealong into the trough and thereafter to be engaged by the cam and rotated, tocause the arm operating mechanism to raise the arm and hold it in such position that the blade is raised above the liquid for the return stroke.

2. In combination, a sewage treatment tank, a scum trough extending thereacross and located above the surface of the liquid therein, and having a ramp extending from below the surface of the liquid to and discharging into the trough, a carriage and means for reciprocating it across the tank toward and from the scum trough, a scum skimmer arm pivoted on the carriage and friction means for resisting its rotation, a skimmer blade carried by the arm, cams located one adjacent the trough, another adjacent the opposite limit of excursion of the carriage, the skimmer blade being adapted to engage and ride up the ramp as it moves toward the trough to force scum upwardly into the trough, one cam being adapted to further rotate the arm to raise the blade above the trough as it moves toward it, another cam being adapted to oppositely engage the arm to rotate it and immerse the blade in the liquid as it approaches the other limit of its ex; cursion.

3. A rectangular settling tank, an influent channel at one end, an eilluent channel at the other end thereof, a scum trough adjacent the ellluent end, means for concentrating the scumand discharging it from the eilluent end comprising tracks arranged along and generally parallel with the eflluent end, a carriage traveling back and forth on the tracks, a skimmer blade supported from the carriage, an incline leading to the scum trough, means for guiding the blade up the incline to force scum into the trough, means for holding the blade in position above the level of the liquid after it has forced scum into the trough, means for forcing the blade downwardly into the liquid as it reaches the end of its excursion away from the trough.

4. A rectangular settling tank, an influent channel at one end, an eiliuent channel at the other end thereof, a scum trough adjacent the eilluent end, means for concentrating the scum and discharging it from the efliuent end comprising tracks arranged along the efliuent end, a carriage traveling back and forth on the tracks, a skimmer blade supported from the carriage, an incline leading to the scum trough, means for guiding the blade up the incline to force scum into the trough, means for holding the blade in position above the level of the liquid after it has forced scum into the trough, means for forcing the blade downwardly into the liquid as it reaches the end of its excursion away'from the trough, the scum trough being parallel with the longitudinal axis of the tank and materially shorter than the tank, means for concentrating sludge in the area passed over by the blade.

5, In a skimmer for sewage tanks and the like, a track above the level of the liquid, a carriage and means for propelling it along the track, a skimmer arm rotatably mounted about an axis on the carriage above the liquid level of and downwardly depending into the tank, a brake drum rigidly connected to the arm, a friction brake adapted at all times to yieldingly hold the drum in whichever position it may be placed, a scum skimmer blade supported on the arm and adapted to be immersed in the liquid, 9. scum trough in the tank in the path of the blade, an inclined ramp extendingfrom below the liquidlevel to the upper edge of the trough above the liquid level, the skimmer blade being adapted as the carriage moves toward the scum trough to engage, and ride up along the ramp, whereby the drum is rotated, means adjacent the trough to engage the skimmer arm as the carriage 'continues its travel to further rotate the drum, means at a point remote from the trough in the path of the arm and blade adapted to rotate them in the opposite direction to immerse the blade in the liquid.

6. In a skimmer for sewage tanks and the like, a track above the level of the liquid, a carriage and means for propelling it along the track, a

skimmer arm rotatably mounted about an axis on the carriage above the liquid level of and downwardly depending into the tank, a brake drum rigidly connected to the arm, a friction brake adapted at all times to yieldingly hold the drum in whichever position it may be placed, ascum skimmer blade supported on the arm and adapted to be immersed in the liquid, a scum trough in the tank in the path of the blade, an inclined ramp extending from below the liquid level to the upper edge of the trough above the liquid level, the skimmer blade being adapted as the carriage moves toward the scum trough to engage, and ride up along the ramp, to scrape scum upwardly therealong and discharge it into the trough and means adjacent the trough forrotating the blade and arm responsive to the movement of the carriage to lift the blade out of the liquid, an'addi- .tional means remote from the trough adapted in response to the movement of the'carriagc to rotate the blade and arm in the opposite direction to immerse the blade in the liquid.

- 1 MARCUS B. TARK. 

